The invention is directed to a room air conditioner and more particularly to a room air conditioner having a dual air flow.
Room air conditioners generally have an air inlet and an air outlet at a front side of the air conditioner which faces the interior of the room when the air conditioner is positioned in a window opening or in a through the wall sleeve. Usually warm air is drawn in through a central portion of the front panel to pass through a filter and through the evaporator coil to be cooled and then is directed by a blower or fan to an outlet or outlets, also in the front panel. The outlet may be a single opening positioned either along a top or bottom edge of the front panel or may be a single opening positioned at one side or the other of the front panel. Occasionally the air from the blower is directed into a manifold type box or plenum chamber and from that chamber it is allowed to exit through the front of the air conditioner through more than one opening. For example in U.S. Pat. No. 3,472,149, assigned to the assignee of the present invention, air is drawn into the air conditioner unit through a lower front grill portion and is redelivered to the room through a grill portion which extends along the top edge of the air conditioner.
In U.S. Pat. No. 2,737,788, air is drawn in from a front lower grill opening, through a filter and the air is pressurized by a fan mounted in a manifold chamber or plenum from which air is permitted to exit through two spaced grills. In U.S. Pat. No. 4,492,094 air is drawn in through a front grill, is pressurized by a fan and exits through a grill 30 located at a bottom edge of the front panel. FIGS. 1 and 2 of that patent illustrate prior art constructions of top and side return of cooled air to the room.
The use of a manifold plenum chamber or similar structure requires an extra space in the air conditioner thereby reducing the compactness of the air conditioner and adding to bulkiness. Also such a structure requires extra parts and weight, thus increasing the cost and complexity of manufacturing. Oftentimes, particularly when the air outlet is positioned on a single side of the air conditioner, the air is drawn into the air conditioner evaporator coil in an off-center fashion thereby reducing the efficiency of the air conditioner.
The air filters generally are mounted behind the front cover and require removal of at least the front cover, and sometimes other structure, in order to access, remove, clean, and replace the filter, thus discouraging checking and cleaning of the filters. A dirty filter, of course, results in less efficient operation of the air conditioner.
The air filter shown in U.S. Pat. No. 2,737,788 does not appear to be viewable or accessible from the exterior of the air conditioner. Similarly, an air filter is disclosed in U.S. Pat. No. 3,274,919 which is not accessible without removal or displacement of parts of the air conditioner. U.S. Pat. No. 2,763,139 provides a filter element carried on a roll. The filter element is to be unrolled occasionally to provide a fresh filter portion in the inlet air flow path and the used portion is to be severed and discarded. To replace the roll it is necessary to remove the cover of the air conditioner.
While air exhaust doors are known for use with room air conditioners, permitting the air conditioner to be used to exhaust air from the room, such features ar usually relatively ineffective in that the exhaust door openings are quite small and are generally not positioned in the direct air flow path of the air leaving the evaporator fan. In U.S. Pat. No. 2,737,788 an exhaust door is provided in a side wall of the plenum chamber well away from the direct air flow path. In U.S. Pat. No. 3,783,637 an exhaust door is provided in a wall which is parallel to the air flow path in an upper air outlet chamber.